[paxswill]

In the US it depends, but I'd venture a guess and say most public university libraries are open at least regularly to the general public. Most of the schools in my state are on this [1] list, and most law libraries I've encountered are also open to the public as well. After hours access is usually restricted to those with a library card though.

[1] http://www.gpoaccess.gov/libraries.html

[coolgeek]

Apparently gpoaccess is no longer being updated and is shutting down in 2012. It looks like the new system is:

http://catalog.gpo.gov/fdlpdir/FDLPdir.jsp?mode=-2